Heretofore, in factories and plants involving machinery producing uncomfortable high levels of noise in their operation there has long been a problem as to the safety and comfort of workers. Industrial noise levels are particularly objectionable in the use of, without exclusion of other devices, 200-ton presses, wood fabricators, nut forming equipment, punches, and dies. In accordance with the Walsh Healey Act, as amended May 8, 1969, occupational noise standards for a person require that he may not work more than eight hours at a maximum of 90 dBA, as measured on the A scale of a sound level meter.
Efforts have been made in the provision of noise enclosure devices such as found in U.S. Pat. No. 3,885,362 entitled "Modular Noise Abatement Enclosure and Joint Seal". In that patent there is provided a noise abatement enclosure having a framework with a top rail and wherein a series of panels side by side are suspended therefrom as a sole support for the panels. The structure disclosed in that patent is complicated and involved as distinquished from the present invention, wherein there is provided a very simplified framework of a hollow tubular construction wherein a series of panels are arranged and supported on the framework so as to enclose the framework without the use of fasteners, providing for easy removability of panels as desired for access to the interior of the enclosure containing a machine, tool or other noisy machinery.